Electromagnetic computations for fusion devices

Among the difficulties in making nuclear fusion a useful energy source, two important ones are producing the magnetic fields needed to drive and confine the plasma, and controlling the eddy currents induced in electrically conducting components by changing fields. All over the world, researchers are developing electromagnetic codes and employing them to compute electromagnetic effects. Ferromagnetic components of a fusion reactor introduce field distortions. Eddy currents are induced in the vacuum vessel, blanket, and other torus components of a tokamak when the plasma current disrupts. These eddy currents lead to large forces. This paper discusses how 3-D codes are being developed to study the currents and forces